The present invention relates generally to an electronic apparatus and more particular to a structure for attaching a cover which is opened/closed when the user additionally provides a memory or replacing a functional component such as a battery pack.
A portable computer, known as a portable electronic apparatus, comprises a computer body and a display unit supported on the computer body. The computer body has a flat box-shaped housing. A keyboard is disposed on the upper surface of the housing.
This type of portable computer is provided with a palm-rest. The palm-rest enhances the operability of the keyboard when used by the operator, or alleviates fatigue of the operator's arms or hands. The palm-rest is located at a front end portion of the housing.
There is also known a conventional portable computer wherein a receptacle, which can accommodate various types of functional components such as a battery pack, a hard-disk drive or a PC card, is formed within the housing and this receptacle is positioned below the palm-rest. In this portable computer, the palm-rest serves also as a cover for opening/closing the receptacle. Accordingly, in most cases, the palm-rest is rotatably or detachably supported on the housing.
In the computer with the rotatable palm-rest, the palm-rest is provided with shaft portions, and bearing holes are formed in the housing. The shaft portions are engaged in the bearing holes so as to be rotatable about their own axes. The palm-rest is thus coupled to the housing. On the other hand, in the computer with the detachable palm-rest, the palm-rest is provided with a plurality of engaging claws at its peripheral portion. These engaging claws are detachably hooked on the housing.
In the case where the rotatable palm-rest is used, engaging portions between the shaft portions and bearing holes are disposed, being spaced apart from each other in the width direction of the palm-rest. These engaging portions are positioned near the boundary between the keyboard and palm-rest. Thus, the palm-rest can be rotated on the shaft portions between a first position where the palm-rest covers the receptacle from above and a second position where the palm-rest turns upward of the keyboard from the receptacle.
According to the conventional portable computer, however, the palm-rest is located immediately before the keyboard. As a result, there is a concern that when the palm-rest has been rotated from the first position to the second position, the palm-rest may interfere with the foremost row of keys of the keyboard. Because of this, the rotational angle of the palm-rest is limited and the palm-rest is permitted to rotate only up to such a degree that the palm-rest is erected just before the keyboard. As a result, the receptacle cannot be widely opened to the above region of the housing, and the palm-rest hinders smooth insertion/removal of the functional component in/from the receptacle.
There is an idea that the angle of opening of the palm-rest is increased by coupling the palm-rest and the housing by means of a link mechanism. In this structure, however, a special link mechanism is required. The structure of the coupling portions of the palm-rest becomes intricate, and a special space for receiving the link mechanism needs to be provided within the housing. Consequently, it becomes very difficult to reduce the manufacturing cost and the size and weight of the housing.
In the case of the portable computer with the detachable palm-rest, it is possible to completely separate the palm-rest from the housing and to widely open the receptacle to the above region of the housing. In this case, however, since the palm-rest is separated from the housing, there is a need to provide a special place for keeping the separated palm-rest. Besides, there is a possibility that the palm-rest may be lost. Furthermore, in order to prevent a theft of the palm-rest, it is necessary to provide the housing with a mechanism for locking the palm-rest. The structure of the housing becomes inevitably intricate and the number of parts increases.
In modern portable computers, a click switch button and a click switch operated by the button are provided at a central portion of the palm-rest. The click switch is electrically connected to a circuit board over a cable within the housing. If the palm-rest is detached from the housing while the presence of the cable is forgotten, a strong tensile force acts on the cable and the cable may be cut or the connecting portion between the cable and the click switch or circuit board may be broken.